Residential Redlining, Neighborhood Trajectory, and Equity of Breast and Colorectal Cancer Care.

Objective: To determine the influence of structural racism, vis-à-vis neighborhood socioeconomic trajectory, on colorectal and breast cancer diagnosis and treatment.

Background: Inequities in cancer care are well-documented in the United States but less is understood about how historical policies like residential redlining and evolving neighborhood characteristics influence current gaps in care.

Methods: This retrospective cohort study included adult patients diagnosed with colorectal or breast cancer between 2010 and 2015 in 7 Indiana cities with available historic redlining data. Current neighborhood socioeconomic status was determined by the Area Deprivation Index. Based on historic redlining maps and the current Area Deprivation Index, we created 4 "neighborhood trajectory" categories: advantage stable, advantage reduced, disadvantage stable, and disadvantage reduced. Modified Poisson regression models estimated the relative risks (RRs) of neighborhood trajectory on cancer stage at diagnosis and receipt of cancer-directed surgery (CDS).

Results: A final cohort derivation identified 4862 cancer patients with colorectal or breast cancer. Compared with "advantage stable" neighborhoods, "disadvantage stable" neighborhood was associated with a late-stage diagnosis for both colorectal and breast cancer [RR = 1.30 (95% CI: 1.05-1.59); RR = 1.41 (1.09-1.83), respectively]. Black patients had a lower likelihood of receiving CDS in "disadvantage reduced" neighborhoods [RR = 0.92 (0.86-0.99)] than White patients.

Conclusions: Disadvantage stable neighborhoods were associated with late-stage diagnoses of breast and colorectal cancer. "Disadvantage reduced" (gentrified) neighborhoods were associated with racial inequity in CDS. Improved neighborhood socioeconomic conditions may improve timely diagnosis but could contribute to racial inequities in surgical treatment.